In devices used in the field of semiconductor or liquid crystal, they are frequently processed by using plasma energy of a halogen-based corrosive gas having a high corrosion property. For example, the fine wiring pattern to be formed by the semiconductor processing device is formed by fine processing (etching) utilizing a strong reactivity of ion or electron excited when a plasma is generated in a strongly corrosive gas atmosphere of a fluorine or chlorine or a mixed gas atmosphere with an inert gas thereof.
In case of such a processing technique, the members or parts (susceptor, electrostatic chuck, electrode and others) disposed in at least a part of the wall face of the reaction vessel or in the inside thereof are easily subjected to an erosion action through a plasma energy, and hence it is important to use a material having an excellent resistance to erosion. As the material satisfying such a requirement, inorganic materials such as a metal having a good corrosion resistance (inclusive of an alloy), quartz and alumina have been used. For example, JP-A-H10-4083 discloses a method wherein the inorganic material is applied onto the surface of the part inside the reaction vessel through PVD process or CVD process or a dense film made of an oxide of an element in Group IIIb of the Periodic Table is formed thereon or a Y2O3 single crystal is applied thereonto. Also, JP-A-2001-164354 discloses technique that the resistance to plasma erosion is improved by applying Y2O3 as an oxide of an element belonging to Group IIIb of the Periodic Table onto the surface of the member through spray process.
However, the conventional method of covering with the oxide of the element of Group IIIb is not yet sufficient in the recent semiconductor processing technique requiring high precision processing and environmental cleanness in a further severer corrosive gas atmosphere.
Also, the member covered with the Y2O3 spray coating as disclosed in JP-A-2001-164354 is demanded to be more improved considering that the recent processing of the semiconductor part is subjected to a plasma etching action at a higher output and under a severer condition alternately and repeatedly using a fluorine gas and a hydrocarbon gas as a processing atmosphere.
For example, the F-containing gas atmosphere causes the formation of a fluoride having a high steam pressure through a strong corrosion reaction inherent to the halogen gas, while the CH-containing gas atmosphere promotes the decomposition of the fluorine compound produced in the F-containing gas and change a part of the film element into a carbide to enhance the reaction of forming the fluoride. Further, the above reaction is promoted under a plasma environment in the F-containing gas atmosphere to form a very severe corrosion environment. Moreover, particles as a corrosion product are produced in such an environment, which drop down and adhere onto a surface of an integrated circuit in the semiconductor product to result in a cause of damaging the device.